FIELD OF THE INVENTION
The invention relates to a drive train controller for a motor vehicle.
Control systems for an engine, a transmission and auxiliary assemblies of a motor vehicle are known to operate largely independently of each other, for example, they constitute the working point and the mode of operation of the controlled assembly largely independently of one another. Devices are available which allow communications between the individual components of the drive train of a motor vehicle, for example in the form of a CAN bus or the like, but they are predominantly used only to exchange sensor data. In addition, the controllers influence one another by communicating during specific operations, for example in order to improve gear shifting performance (comfort) the engine torque is reduced when the gear transmission ratio is changed.
Further examples include the control of engine torque during braking or a reduction of the engine torque during the occurrence of drive slip. A proposal to interlink systems in an automobile, where the interlinking is aimed at obtaining an integrated drive train controller for a motor vehicle, is known from an article by R. Stuttgart, titled "Systemvernetzung im Automobil" [Automobile System Networks], F & M 101(1993)3, pages 87 to 90). The article teaches using the position of the gas pedal to be interpreted as an indicator of an amount of wheel torque desired by the driver and is used to calculate set point values for the engine and for the transmission of the motor vehicle. The objective of the article is the optimization of the engine controller, electronic gas pedal and transmission controller subsystems which are proposed therein to reduce the fuel consumption and to improve the driving characteristics of the motor vehicle, in particular in relation to the spontaneous reaction to movements of the gas pedal.
In the drive train controller disclosed in German Published, Non-Prosecuted Patent Application DE 196 37 210 A1, corresponding to pending U.S. application Ser. No. 08/937,253, filed Sep. 12, 1997, the central reference variable is a set point wheel torque which is defined by the driver by a specific position of the accelerator pedal (steady-state) and by accelerator pedal dynamics, i.e. by the manner and speed of changes in the position of the accelerator pedal.